Wire straighteners



July 18, 1967 T. w. KAESTNER WIRE STRAIGHTENERS 5 Sheets-Sheet 1 Original Filed Aug. 30, 1963 5 Sheets-Sheet 2 T. W. KAESTNER WIRE STRAIGHTENERS July 18, 1967 Original Filed Aug. 30

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44w K/A/fl N 5? is United States Patent 3,331,231 WIRE STRAIGHTENERS Thankmar Walter Kaestner, Bridgeport, Conn., assignor to The A. H. Nilson Machine Company, Shelton, Conn., a corporation of Connecticut Continuation of application Ser. No. 305,797, Aug. 30, 1963, now Patent No. 3,277,682, dated Oct. 11, 1966. This application June 6, 1966, Ser. No. 555,581

4 Claims. (Cl. 72-79) This application is a continuation of my copending application, Ser. No. 305,797, filed Aug. 30, 1963, and now Patent No. 3,277,682, issued on Oct. 11, 1966, and titled Wire Straighteners.

This invention relates to wire straightening and, more particularly, to that type of apparatus known in the art as rotary wire straighteners as opposed to roll straighteners.

The manufacturer of wire products customarily buys the wire he requires rolled upon a spool or reel. Before this wire can be fed to the wire forming machinery where it is shaped into the final product, it must first be straightened to remove the curve it has acquired from reel storage. One method of achieving this straightening is to pass the wire through a rotary wire straightener. The operation of a prior art rotary wire straightener may be understood by considering the Wire to pass through the center of a hollow shaft. Extending inwardly from the sides of the shaft are a number of pairs of straightening blocks. One block of each pair extends radially inwardly from the side of the shaft in directly opposed relationship to a similar block that extends inwardly from the opposite side of the shaft. The two blocks of each pair are formed and spaced in such a manner as to provide a wire passage between them. The pairs of blocks are positioned axially along the shaft and are adjusted so that a wire which passes through the passageway thus formed is forced to snake or acquire a sinuous configuration as it passes between the pairs of straightening blocks. The wire is then caused to move longitudinally through the shaft by external means which also keeps the wire taut. As the wire moves longitudinally through the shaft the shaft is caused to rotate. The straightening block also rotate, giving a cranking motion to the wire which efficiently straightens it.

Rotary wire straighteners of the foregoing type are relatively successful in straightening large size wire. The term large size wire refers to wire having a diameter greater than approximately .032 inch. When prior art rotary wire straighteners are used to straighten wire much smaller than this (depending on the wire material) they tend to twist and break the wire and give unsatisfactory straightness. The prior art straighteners are also time consuming to adjust and are diflicult to rewire when small diameter Wire breaks during the straightening operation.

In order to overcome some of the above difficulties when straightening smaller wire, it has been proposed to employ counter-rotating straighteners. Straightener of this type comprise a pair of assemblies of the type re ferred to above wherein the two shafts are aligned but rotate in opposite directions, the wire passing through one set of straighteners and then through another set. Although counter-rotating straighteners of this type neutralize the torque on the wire between the counterrotating shafts, they have otherwise proved relatively unsuccessful because they, by their design, continued to twist the wire, and small Wire in particular, to destruction. Furthermore, the equipment is large and expensive and special problems arise when straightening small diameter, easily breakable wire because it is difiicult to rethread the wire.

Because of the present trend toward miniaturization,

3,331,231 Patented July 18, 1967 it ha become important to provide suitable means for straightening small diameter wire. A simple reduction in size of the straightener is not sufficient. The reason for this is that a wires resistance to torsion and bending is proportional to its diameter raised to the third power (d Accordingly, a reduction in wire diameter requires a much more drastic reduction in the dimension of the straightener. The efficacy of a straightener depends on the angle formed between a given segment of the wire and the axis of rotation of the straightener. For wire of a given size and material, this angle should remain constant. However, since the resistance of wire to torsion and bending stresses is inversely proportional to the distance over which the stresses are applied it is important that all sections of wire in a rotary straightener be kept as short as possible, so that the wire can offer a maximum of resistance to the destructive twisting forces relevant in its operation.

Accordingly, it is a primary object of this invention to provide an improved wire straightener.

Other objects are to provide such a straightener which is particularly well adapted to straightening small diamctcr wire; which is well adapted to the counter-rotating technique; which does not unduly twist the wire; wherein the twisting moment is transmitted over a minimum distance; wherein the straightening blocks are easily adjustable; whcrein a wire can easily be rethreaded without affecting the setting of the straightening blocks; wherein the straightening blocks are easily accessible; and wherein the setting of the straightening blocks is easily reproducible.

The manner in which the foregoing objects are achieved will he more apparent from the following descrpition, the appended claims, and the figures of the attached drawings, wherein:

FIG. 1 is a side elevational view of a wire straightening machine in accordance with this invention, portions thereof being broken away;

FIG. 2 is a front elevational view of the machine of FIG. 1, portions thereof being broken away;

FIG. 3 is an enlarged side view of the straightener portion of the machine illustrated in FIGS. 1 and 2;

FIG. 4 is an enlarged detail of a portion of the invention, sections being broken away for clarity;

FIG. 5 is an enlarged rear view of the straightener portion of FIG. 3;

FIG. 6 i a cross sectional view of the straightener portion illustrating the construction of the straightener arbors;

FIG. 7 is a cross sectional view taken along the line 7-7 of FIG. 6;

FIG. 8 is a perspective view illustrating the straightening blocks utilized in the present invention;

FIG. 9 is a schematic illustration showing the manner of operation of the straightener of this invention; and

FIG. 10 i a schematic illustration showing the manner of operation of counter-rotating straighteners in accordance with the prior art.

With particular reference to FIGS. 1 and 2, there is illustrated a wire straightening machine embodying the present invention and comprising a cabinet 10 mounted on a pair of wide legs 12 which may be adjustably positioned on the cabinet 10 in accordance with the ultimate desired height of the machine. Enclosed within the cabinet 10 is an electrical drive motor 14 bolted to a cantilevered base plate 16 which is secured at the rear of the cabinet by bolts 18 and is rendered vertically adjustable by means of a jack bolt 20. The motor 14 is designed for quick starting and also includes a brake for stopping the motor rapidly when power is cut off. The front wall of cabinet 16 carries a control box 22 and suitable wiring (not shown) is provided between box 22, motor 14, and an external power supply. The shaft of motor 14 carries a three-step pulley 24. One side wall of cabinet is provided with a vertical slot 26. An internally mounted bracket 28 includes a clamping screw 30 which extends through slot 26. A manual clamping nut 32 allows bracket 28 to be vertically positioned relative to the cabinet 10. On the inner side of bracket 28 there is mounted a shaft 34 which carries an idler pulley 36. It will be noted that the idler pulley 36 is mounted above the pulley 24 of the motor 14 and the two are mounted to rotate about parallel axes. The axes of rotation of these pulleys are at 90 to the direction of travel of the wire to be straightened, as will be more fully set out below.

Passing through the front wall of cabinet 10 is a wire spool arbor 38. The inner end of the arbor 38 passes through a clamp 40 mounted on the top of cabinet 10 and is fixed in position by means of a releasable clamping screw 42. A pad 44 on the front of cabinet 10 encircles the spool arbor 38 and the wire spool 46 which is rotatably mounted on the arbor 38 bears against the pad 44. The outer end of arbor 38 is threaded to carry a tension adjusting nut 48 which compresses a coil spring 50 against a thrust bearing 52 which bears against wire spool 46. The front and back walls of the cabinet 10 support the ends of a shaft 54. That end of shaft 54 which is supported by the front of cabinet 10 carries a sleeve bearing 56 which forms the pivotal portion of an L-shaped crank 58. The longer arm 58a of crank 58 extends in a generally horizontal direction from the pivot bearing 56 and carries at its opposite end a shaft 60 which extends through a slot 62 cut in the front wall of the cabinet 10. The shaft 60 is fixed relative to the arm 58a and an idling tension pulley 64 is mounted for free rotation around and movement along the shaft 60. Arm 58b of crank 58 extends in a generally vertical direction from the pivot bearing 56 and its opposite end is connected between stressed coil springs 66, 68 which extend between the left and right sides of the cabinet 10. Arm 58b is connected directly to the end of spring 66 and, by means of a suitable linking wire 70. to the end of spring 68. The tension adjusting knob 72 is threaded and screwed to the end of a bolt 74 which is secured to the end of spring 68. Bolt 74 includes a keyway and is advanced into or out of the cabinet 10 by reason of its engagement with keyed bushing 76.

Mounted atop cabinet 10 is the straightening mechanism proper which is here given the general designation S. The straightening mechanism S is shown in enlarged detail in FIG. 3. to which reference may be had for a more complete understanding of its construction. The straightening mechanism includes an entry bracket 78 and an exit bracket 80, each of which is securely mounted to the top of cabinet 10 by means of suitable bolts 82.

The entry bracket 78 includes an opening in which is positioned a cylindrical bushing 84 which is drilled to provide a passageway 98 for an entering wire 86. The central portion of bushing 84 is milled away to provide a lubrication pocket 88 which communicates with the top of entry bracket 78 by virtue of a further vertical opening 90. The front of entry bracket 78 carries the base 92 of an anti-twist wire roll 94. The base 92 is secured to the bracket 78 by means of suitable bolts 96 which are so arranged that the roll 94 can be positioned to rotate about either a vertical or a horizontal axis. Also included in the base 92 is an opening which encircles bushing 84 and permits wire strand 86 to pass from the roll 94 through the bushing. The inner side of bracket 78 is provided with a shelf 100 for a purpose to be shortly explained.

The exit bracket 80 carries on its inner side a shelf 102 which is generally similar to shelf 160. The upper portion of bracket 80 is drilled to receive a wire exit bushing 104 mounted therein by a suitable set screw 106. The base portion 80a of bracket 80 is drilled to receive a pivot pin 108 as is best illustrated in FIG. 5.

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Pivot pin 108 is secured in position by means of its hexagonal head 108a and its threaded end 108b which carries a nut 110. Mounted on pivot pin 108 between nut 110 and the base portion 80a of exit bracket 80 is the end of a lever arm 112. Pivotally secured to the opposite end of lever arm 112 is an oscillating drive member 114.

The shelves 100, 102 of entry bracket 78 and exit bracket 80 support the opposite ends of a slide bar 116 which is of generally square cross section and is secured to the shelves by means of suitable countersunk bolts 118. A straightener cradle housing 120 is mounted for reciprocation along slide bar 116. The cradle housing 120 may be of cast metal and carries an entrance bearing housing 122 and an exit bearing housing 124 which are separated from one another, as illustrated in FIG. 3. The lower portion of cradle housing 120 includes depending side walls 126, 128 which straddle the slide bar 116. The cradle housing is further secured to the slide bar by means of a lower plate 130 which is affixed to the side walls by means of suitable bolts 132. The saddle 134 that is formed between the side walls 126, 128 on the body of the cradle housing 120 forms a bearing surface and may be suitably grooved for efficient lubrication. A driver arm 136 is secured to cradle housing 120 by a suitable pivot pin 138 and to the midpoint of lever arm 112 by a drive pin 140. The straightening mechanism S is covered by a safety guard 141.

The construction of the wire straightener mechanism is most clearly shown in the enlarged views of FIGS. 6 and 7. The entrance bearing housing 122 encloses a ball bearing 142 which rotatably supports a hollow entrance shaft 144 on the outer (left) end of which is mounted a drive pulley 146 which is keyed to shaft 144 and secured by means of a lock nut 148 mounted on the threaded end of the shaft. The inner end of the entrance shaft 144 is slotted so as to form an arbor 150 having a rectangular opening 152 extending diametrically through it. The extreme right hand end of the arbor 150 is enclosed by a circular end plate 154. The arbor 150 is further encircled by a bearing shield 156 mounted on the inner surface of the entrance bearing housing 122. Bearing shield 156 is generally disc-shaped but includes a milled recess 158 which has a width greater than that of the arbor and extends diametrically across the face of the shield. Enclosed within the hollow shaft 144 is a tubular wire guide 160. The wire guide 160 has a flared end 160a which communicates with the opening 152 in arbor 150 and is supported within the shaft at its left end by a threaded sleeve 161.

In direct alignment with the entrance shaft 144 and its arbor 150 is a similarly constructed exit shaft and arbor which is in reversed relationship but of otherwise similar construction. Accordingly, the elements of the exit shaft and its arbor which are mounted within the exit bearing housing 124 are given similar numbers but with a prime added. Thus it will be noted from FIG. 6 that the exit bearing housing 124 encloses a rotating shaft 144' which supports an arbor 150' and is otherwise similar to the mechanism previously described. In the illustration of FIG. 6, the shafts and arbors are shown in positions rotated 90 from one another in order to more clearly illustrate the internal construction. It is important to note that the inner ends of the arbors are separated from one another by a minimum distance. Each of the arbors 150, 150' encloses within its central opening a pair of opposed wirestraightening magazines. Each such pair includes a two-block magazine 162, 162' and a three-block magazine, of which only magazine 164' located in the exit arbor is indicated in FIG. 6. The four magazines have similar external appearances, being rectangular prismatic metal blocks having cross sectional dimensions which permit their insertion into the opening of their respective arbors. Each of the magazines is provided with a lip 166', 168', as shown in FIG. 7. This lip extends the length of the magazine and abuts against the arbor which the magazine is inserted into the central opening so that the two magazines of a pair meet at the center line of the arbor, as illustrated in FIG. 7. The outermost surface of each of the magazines includes a step 170', 171', the magazines thus being thicker toward the inner end of the respective arbors. Each of the arbors 150, 150' is provided with a keyway 172, 172', 174, 174'. The keyways of each pair are diametrically opposed to one another and lie in a plane rotated 90 from the central plane of the magazine-containing opening in the respective arbor. This is illustrated most clearly in FIG. 7. The magazines are retained within the arbors by means of identical retaining rings 176, 176'. The retaining rings are generally oblong in shape. Ring 176' is illustrated in FIG. 7 and will be described. Its central opening is essentially hexagonal so as to define a pair of opposed straight edges 178', 180', which engage the outer surfaces of the magazines 162', 164' at the respective steps 170 171'. Each of the retaining rings further includes a pair of keys 182', 184', which engage the corresponding keyways 172, 174' to retain the ring in a fixed circumferential relationship relative to the arbor. The outer width of the rings is such that they may be easily slid into the milled recesses 158, 158 of the bearing shields 156, 156'. In addition to these features, each of the retaining rings 176, 176' is milled along its diameter so as to provide a pair of opposed radial recesses 186', 188 of a width greater than the thickness of the retained magazines. It is important to note from FIG. 6 the relationship between a pair of magazines and its retaining ring, arbor, and bearing shield. For example, the central recess of the arbor 150 is poistioned axially from the inner surface of milled recess 158 a distance that is greater than the thickness of that portion of retainer ring 176 underlying the radial recesses 186, 188. Accordingly, when the arbor 150 is rotated by 90 the ring 176' will be slidable into the milled recess 158' and each of the magazines 162, 164 will then be removable from their arbors through either recess 186' or 188'. This is illustrated in FIG. 6 by means of the broken lines 176a which outline such a position of the left hand retaining ring 176.

As has been stated, each of the magazines 162, 162', 164, 164' essentially comprise a prismatic metallic block of rectangular cross section. The magazines 162', 164' contain axially displaced rectangular passages 190, 192'. These passages extend outwardly from the inner surface of the magazine and each contains a wire straightening block 194. The recesses and blocks of the two and three block magazines are so disposed that the ends of the blocks contained in opposing magazines interlock with one another, as shown in FIG. 6. Each of the blocks 194 is backed by a recessed adjusting screw 196 which is threaded into the magazine in an opening which communicates with the radial recess for the corresponding block. The additional passages 198 have no functional purpose but serve to lessen the weight of the magazines. The construction of the wire straightening blocks 194 is most clearly illustrated in FIG. 8 wherein three interlocking blocks are illustrated but separated from one another for ease of viewing. Each block is essentially a square prism having a polished half-round groove 194a, 19411 in each end. The blocks are double-ended in order that they may be reversed to equalize wear and reduce the necessity for replacement. The blocks may be made of any suitable materials, for example, sintered ceramic, Stellite, carbide, nylon, Teflon, or lignum vitae.

Referring back to FIG. I to complete the description of the apparatus, a fiat belt 200 passes with a 90 twist from the three-step pulley 24 of motor 14 upwardly and over the drive pulleys 146, 146'. The belt then passes downwardly from each of pulleys 146, 146 and passes around the idler pulley 36, once again with a 90 twist. Accordingly, it will be obvious that as motor 14 rotates,

the belt 200 will impart opposite rotation to the pulleys 146, 146', causing counter-rotation of the arbors 150, 150'.

Before proceeding to a detailed discussion of the operation of the invention, attention is directed to FIGS. 9 and 10 which illustrate the principles which render this invention a great advance over the prior art. FIG. 10 illustrates the prior art in the field of counter-rotating wire straighteners. In the prior art apparatus of FIG. 10, the wire 86 being straightened passes between successive pairs of axially spaced straightening blocks 202. The blocks designated a are located within one arbor and the blocks designated b are located within another arbor, the two arbors being counter-rotated. Each of the arbors includes a section of hollow shaft at either end. Accordingly, they cannot be positioned closely together but are separated a distance L. Furthermore, the individual pairs of blocks within each arbor are separated from one another. The angle A shown in FIG. 10, known as the bending angle, is the important consideration in straightening wire. The distance R is the cranking distance or moment arm and twisting of wire 86 tends to occur as a result of the rotational forces applied to the wire at distance R. The long span of wire along distance L also presents essentially no resistance to twisting.

In FIG. 9 a schematic diagram of the straightener of the invention is illustrated. In this straightener, rather than having opposing pairs of blocks, the blocks 194 on opposite sides of wire 86 are interlocked so as to substantially reduce the axial length taken by the blocks along the wire. The angle A required for straightening the wire is maintained at the same value as shown in FIG. 10. However, the moment arm tending to twist the wire is substantially reduced from R to r, because of closer block spacing. Furthermore, since the two arbors are positioned closely adjacent one another, the distance 1 between the counter-rotating sets of straightening blocks is also substantially reduced. The short space of wire along distance 1 provides substantial resistance to twisting in this case.

The operation of the disclosed embodiment of the invention will now be explained. To prepare the machine, the clamping screw 42 is released and the spool arbor 38 is withdrawn from the front of the cabinet 10. The wire spool 46 is placed on the spool arbor and the arbor replaced in the cabinet and locked by clamping screw 42. The wire spool then rests between the pad 44 and the spring-loaded thrust bearing 52 so that the freedom of rotation of wire spool 46 is retarded by the amount of loading provided by the coil spring 50. This is adjustable by means of the tension adjusting nut 48. The wire 86 from spool 46 passes around the tension pulley 64 on its way to the anti-twist roll 94. As the arm 58b of the L-shaped crank 58 is positioned between the tension springs 66, 68, the pulley 64 tends to fioat" in a central position, and the tension adjusting nut 72 is adjusted so that tension pulley 64 exerts a desired downward force against the wire 86. The wire then passes from the tension pulley 64 to the anti-twist roll 94. The anti-twist roll 94 has a peripheral V groove with a relatively sharp angle so that as wire 86 passes round the anti-twist roll 94 under tension, it is gripped so that twisting forces applied to the departing strand are not passed around the roll to the upcoming portion of the wire strand. From antitwist roll 94 the wire 86 passes through the opening 98 in bracket 78 through lubrication pocket 88 and continues into the threaded insert 161, the tubular wire guide 160, and on into the straightener proper. Lubrication pocket 88 and vertical opening 90 are packed with lubricantsoaked waste or similar material for lubricating the moving wire.

The threading of the wire from the wire spool 46 to its entry into the straightener mechanism accomplishes some important functions required for the straightening of thin wires. First, if the drag exerted on the wire spool 46 by thrust bearing 52 and the downward force exerted by the tension pulley 64 are properly adjusted, a pull on the wire as it leaves the straightener will cause a smooth and shock-free acceleration of the wire spool 46. This is because the tension pulley 64 will give in an upward direction until its increasing spring load overcomes the drag and inertia of the spool. Conversely, if the pull on the wire leaving the straightener suddenly decreases or stops, the wire will not become slack because the tension roll will keep it tight. Furthermore, as has been explained, any tendency for the wire to twist and any torque applied to the wire by the straightener mechanism will not pass the anti-twist roll 94.

The four magazines 162, 162', 164, 164 are removed from their respective arbors 150, 150' by sliding the retaining rings 176, 176' into the milled recesses 158, 158' in bearing shields 156, 156'. The magazines are thereby freed for removal radially outward from the arbor. It is also important to note that by this novel construction an effective safety feature is introduced in that the retaining rings 176, 176' not only release their respective magazines, but also lock their arbors against rotation by reason of their insertion into the milled recesses. The magazines may thereupon be removed and the wire can be easily and safely threaded through the wire guide 160, the central portions of the arbors 150, 150', and Wire guide 160'. The wire passes through the wire exit bushing 104 to a suitable wire forming machine which is not a part of this invention and which is not illustrated.

When the wire has been threaded, the magazines may be reinserted into their respective arbors. The retaining rings 176, 176' are slid axially against the steps 170', where they retain the magazines in position. The set screws 196 behind the straightening blocks 194 are advanced against the wire 86 so that the former straight line of the wire path is converted to a serpentine path.

The wire 86 is pulled through the straightener by external means which are not illustrated. As the wire advances through the straightener, motor 14 is started and the belt 200 in passing over the drive pulleys 146, 146' imparts counter-rotating motion to the two arbors which thereby rotate the blocks and straighten the wire. As the arbors 150, 150' rotate, the centrifugal force exerted on the magazines causes them to be forced radially outward and against the straight adges 178, 178 180, 180' of the retaining rings 176, 176. This causes the retaining rings and magazines to lock firmly together during the straight ening process.

In addition to the rotational motion of the arbors, an oscillating motion may be imparted to the cradle housing 120. This may be accomplished, for example, by imparting an oscillatory motion to the drive member 114 from an external source, such as the wire forming machine. This oscillatory motion causes a back-and-forth rotation of lever arm 112 about pivot pin 108 and driver arm 136 imparts linear oscillation to the straightener cradle housing 120 by moving it back and forth along the slide bar 116.

The present invention has a number of important advantages over straighteners known in the prior art. For example, this invention has been found useful for straightening wire having a diameter as small as .004 inch. The magazines containing the straightening blocks are easily removable and are locked in place by a retaining member which also serves as a safety device when the magazines are removed. The setting of the straightening blocks can be easily reproduced by means of a micrometer and interchangeable magazines may be used for different sized wire. The interlocking placement of the straightening blocks is such that there is no intervening open space between them, thus obtaining the shortest possible crank leverage for any given bending angle while retaining the maximum torsional strength of the wire. Furthermore, the use of two arbors which are supported at their outer ends so that the counter-rotating magazines are in close proximity, reduces the twisting tendencies of the wire.

Many other advantages of this invention will also be apparent to those skilled in the art. Accordingly, it is to be understood that the present description merely discloses a single preferred embodiment of the invention and that various modifications and changes will be apparent to those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the foregoing description is illustrative only, rather than limiting. This invention is limited only by the scope of the following claims.

I claim:

1. A wire straightener for relieving residual curvature in axially-advancing fine wire, comprising, in combination:

(A) two axially-spaced counter-rotating pairs of diametrically opposed straightening block means, each pair being supported for co-axial rotation about the wire,

(B) and drive means for rotating these axially-spaced pairs in opposite directions, including (1) a single endless drive belt, drivingly engaged with separate drive sheaves each connected to drive one of the axially-spaced pairs, and having two opposite bights therebetween,

(2) a power sheave drivingly engaged with one bight of the belt (3) and at least one idler sheave positioned for tensioning engagement with the other bight of the belt.

2. The combination defined in claim 1 wherein (A) the axially-spaced pairs of straightening block means are mounted on arbors each respectively drivingly connected to one of the drive sheaves and journalled for co-axial counter-rotation about the advancing Wire surmounting a cabinet,

(B) with the endless drive belt overlying the drive sheaves and having its two bights depending within the cabinet for engagement with the power sheave and the idler sheave therein.

3. The combination defined in claim 2 wherein the idler sheave is adjustably mounted within the cabinet to provide predetermined variation in tension of the drive belt.

4. The combination defined in claim 1 wherein the axially-spaced pairs of straightener block means are journalled for rotation in a cradle housing slidably mounted on a slide bar for reciprocating movement along a path parallel to the axis of the advancing wire, and wherein the power sheave and idler sheave are rotatably mounted on axes substantially perpendicular to and substantially spaced away from the axis of the advancing wire, whereby driving engagement of the drive belt with all sheaves continues throughout the axial reciprocating movement of the drive sheaves.

References Cited UNlTED STATES PATENTS 1,538,325 5/1925 Higgins 7: 79

CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner. 

1. A WIRE STRAIGHTENER FOR RELIEVING RESIDUAL CURVATURE IN AXIALLY-ADVANCING FINE WIRE, COMPRISING, IN COMBINATION: (A) TWO AXIALLY-SPACED COUNTER-ROTATING PAIRS OF DIAMETRICALLY OPPOSED STRAIGHTENING BLOCK MEANS, EACH PAIR BEING SUPPORTED FOR CO-AXIAL ROTATION ABOUT THE WIRE, (B) AND DRIVE MEANS ROTATING THESE AXIALLY-SPACED PAIRS IN OPPOSITE DIRECTIONS, INCLUDING (1) A SINGLE ENDLESS DRIVE BELT, DRIVINGLY ENGAGED WITH SEPARATE DRIVE SHEAVES EACH CONNECTED TO DRIVE ONE OF THE AXIALLY-SPACED PAIRS, AND HAVING TWO OPPOSITE BIGHTS THEREBETWEEN, 